<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>H5标签</title>
    <style>
        body,html {
            width:100%;
            height: 100%;
            padding: 0;
            margin: 0;
        }
        .content {
            width: 100%;
            height: 100%;
            overflow: auto;
            background: grey;
        }
        .tag {
            width: calc(100% - 20px);
            height: 100px;
            margin: 5px 10px;
            background: honeydew;
        }
        .describe {
            width: 100%;
            height: 30px;
            text-align: center;
            line-height: 30px;
            background: cadetblue;
        }
        .tag_content {
            width: 100%;
            height: calc(100% - 30px);
            display: flex;
            align-items: center;
            justify-content: center;
        }

    </style>
</head>
<body>
    <div class="content">
        <div class="tag" style="display: none;">
            <!-- 注释标签：定义注释 -->
            <!--  -->
            <!-- 文档类型标签：定义文档类型 -->
            <!-- <!DOCTYPE html> 用于声明文档最前面 -->
        </div>
        <div class="tag">
            <!-- a 标签 定义超文本链接 -->
            <div class="describe">
                <a href="https://www.runoob.com/tags/tag-a.html" target="_blank">a标签详情</a>
            </div>
            <div class="tag_content">
                <a href="www.baidu.con">百度一下</a>
            </div>
        </div>
    </div>
</body>
</html>